Researchers explore ways to stretch, blur and even reverse quantum time flow.
Researchers explore ways to stretch, blur and even reverse quantum time flow.
In new research published in Physical Review X, scientists have designed quantum control protocols that generate processes more consistent with time flowing backward than forward. The protocols — techniques to control quantum systems — modify a quantum system’s “arrow of time,” the concept of time as moving in one forward direction. The work opens up possibilities for energy extraction from quantum systems and for quantum state preparation.
A quantum system, such as a collection of qubits, is governed by the laws of quantum mechanics. The team’s control protocols can prevent the emergence of the arrow of time in a quantum system or even invert its direction — that is, cause quantum time to appear to flow in reverse. As an application of their research, the team leveraged their control protocols to design a measurement engine that extracts energy from quantum measurements performed on the system.
“Unlike phenomena we observe around us, at the microscopic level most fundamental laws of physics see forward and backward movement in time as physically possible,” said Los Alamos National Laboratory physicist Luis Pedro García-Pintos. “In other words, those laws of physics are symmetrical under time reversal; the equations work just as well if you reverse time. For quantum systems, which operate at that microscopic level, the tools we’ve constructed can manipulate the perceived arrow of time, leading to surprising, novel ways to control quantum systems.”
Read More: Los Alamos National Laboratory
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